/*
* Taken from NetBSD and stripped of the relocations not needed on RTEMS.
*/
/* $NetBSD: mdreloc.c,v 1.43 2010/01/13 20:17:22 christos Exp $ */
/*-
* Copyright (c) 1999, 2002 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Paul Kranenburg and by Charles M. Hannum.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#include <stdio.h>
#include <rtems/rtl/rtl.h>
#include "rtl-elf.h"
#include "rtl-error.h"
#include "rtl-trace.h"
#include "rtl-unwind.h"
#include "rtl-unwind-dw2.h"
/*
* The following table holds for each relocation type:
* - the width in bits of the memory location the relocation
* applies to (not currently used)
* - the number of bits the relocation value must be shifted to the
* right (i.e. discard least significant bits) to fit into
* the appropriate field in the instruction word.
* - flags indicating whether
* * the relocation involves a symbol
* * the relocation is relative to the current position
* * the relocation is for a GOT entry
* * the relocation is relative to the load address
*
*/
#define _RF_S 0x80000000 /* Resolve symbol */
#define _RF_A 0x40000000 /* Use addend */
#define _RF_P 0x20000000 /* Location relative */
#define _RF_G 0x10000000 /* GOT offset */
#define _RF_B 0x08000000 /* Load address relative */
#define _RF_U 0x04000000 /* Unaligned */
#define _RF_SZ(s) (((s) & 0xff) << 8) /* memory target size */
#define _RF_RS(s) ( (s) & 0xff) /* right shift */
static const uint32_t reloc_target_flags[] = {
0, /* NONE */
_RF_S|_RF_A| _RF_SZ(8) | _RF_RS(0), /* RELOC_8 */
_RF_S|_RF_A| _RF_SZ(16) | _RF_RS(0), /* RELOC_16 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* RELOC_32 */
_RF_S|_RF_A|_RF_P| _RF_SZ(8) | _RF_RS(0), /* DISP_8 */
_RF_S|_RF_A|_RF_P| _RF_SZ(16) | _RF_RS(0), /* DISP_16 */
_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* DISP_32 */
_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP_30 */
_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WDISP_22 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(10), /* HI22 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 22 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* 13 */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* LO10 */
_RF_G| _RF_SZ(32) | _RF_RS(0), /* GOT10 */
_RF_G| _RF_SZ(32) | _RF_RS(0), /* GOT13 */
_RF_G| _RF_SZ(32) | _RF_RS(10), /* GOT22 */
_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(0), /* PC10 */
_RF_S|_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(10), /* PC22 */
_RF_A|_RF_P| _RF_SZ(32) | _RF_RS(2), /* WPLT30 */
_RF_SZ(32) | _RF_RS(0), /* COPY */
_RF_S|_RF_A| _RF_SZ(32) | _RF_RS(0), /* GLOB_DAT */
_RF_SZ(32) | _RF_RS(0), /* JMP_SLOT */
_RF_A| _RF_B|_RF_SZ(32) | _RF_RS(0), /* RELATIVE */
_RF_S|_RF_A| _RF_U|_RF_SZ(32) | _RF_RS(0), /* UA_32 */
};
#define NOT_CURRENTLY_USED_BUT_MAYBE_USEFUL
#ifdef NOT_CURRENTLY_USED_BUT_MAYBE_USEFUL
static const char *reloc_names[] = {
"NONE", "RELOC_8", "RELOC_16", "RELOC_32", "DISP_8",
"DISP_16", "DISP_32", "WDISP_30", "WDISP_22", "HI22",
"22", "13", "LO10", "GOT10", "GOT13",
"GOT22", "PC10", "PC22", "WPLT30", "COPY",
"GLOB_DAT", "JMP_SLOT", "RELATIVE", "UA_32"
};
#endif
#define RELOC_RESOLVE_SYMBOL(t) ((reloc_target_flags[t] & _RF_S) != 0)
#define RELOC_PC_RELATIVE(t) ((reloc_target_flags[t] & _RF_P) != 0)
#define RELOC_BASE_RELATIVE(t) ((reloc_target_flags[t] & _RF_B) != 0)
#define RELOC_UNALIGNED(t) ((reloc_target_flags[t] & _RF_U) != 0)
#define RELOC_USE_ADDEND(t) ((reloc_target_flags[t] & _RF_A) != 0)
#define RELOC_TARGET_SIZE(t) ((reloc_target_flags[t] >> 8) & 0xff)
#define RELOC_VALUE_RIGHTSHIFT(t) (reloc_target_flags[t] & 0xff)
static const int reloc_target_bitmask[] = {
#define _BM(x) (~(-(1ULL << (x))))
0, /* NONE */
_BM(8), _BM(16), _BM(32), /* RELOC_8, _16, _32 */
_BM(8), _BM(16), _BM(32), /* DISP8, DISP16, DISP32 */
_BM(30), _BM(22), /* WDISP30, WDISP22 */
_BM(22), _BM(22), /* HI22, _22 */
_BM(13), _BM(10), /* RELOC_13, _LO10 */
_BM(10), _BM(13), _BM(22), /* GOT10, GOT13, GOT22 */
_BM(10), _BM(22), /* _PC10, _PC22 */
_BM(30), 0, /* _WPLT30, _COPY */
-1, -1, -1, /* _GLOB_DAT, JMP_SLOT, _RELATIVE */
_BM(32) /* _UA32 */
#undef _BM
};
#define RELOC_VALUE_BITMASK(t) (reloc_target_bitmask[t])
uint32_t
rtems_rtl_elf_section_flags (const rtems_rtl_obj_t* obj,
const Elf_Shdr* shdr)
{
return 0;
}
bool
rtems_rtl_elf_rel_resolve_sym (Elf_Word type)
{
return RELOC_RESOLVE_SYMBOL (type) ? true : false;
}
bool
rtems_rtl_elf_relocate_rela (const rtems_rtl_obj_t* obj,
const Elf_Rela* rela,
const rtems_rtl_obj_sect_t* sect,
const char* symname,
const Elf_Byte syminfo,
const Elf_Word symvalue)
{
Elf_Addr *where;
Elf_Word type, value, mask;
Elf_Addr tmp = 0;
where = (Elf_Addr *) (sect->base + rela->r_offset);
type = ELF_R_TYPE(rela->r_info);
if (type == R_TYPE(NONE))
return true;
/* We do JMP_SLOTs in _rtld_bind() below */
if (type == R_TYPE(JMP_SLOT))
return true;
/* COPY relocs are also handled elsewhere */
if (type == R_TYPE(COPY))
return true;
/*
* We use the fact that relocation types are an `enum'
* Note: R_SPARC_6 is currently numerically largest.
*/
if (type > R_TYPE(6))
return false;
value = rela->r_addend;
/*
* Handle relative relocs here, as an optimization.
*/
if (type == R_TYPE (RELATIVE)) {
*where += (Elf_Addr)(sect->base + value);
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: reloc relative in %s --> %p",
rtems_rtl_obj_oname (obj), (void *)*where);
return true;
}
if (RELOC_RESOLVE_SYMBOL (type)) {
/* Add in the symbol's absolute address */
value += symvalue;
}
if (RELOC_PC_RELATIVE (type)) {
value -= (Elf_Word)where;
}
if (RELOC_BASE_RELATIVE (type)) {
/*
* Note that even though sparcs use `Elf_rela'
* exclusively we still need the implicit memory addend
* in relocations referring to GOT entries.
* Undoubtedly, someone f*cked this up in the distant
* past, and now we're stuck with it in the name of
* compatibility for all eternity..
*
* In any case, the implicit and explicit should be
* mutually exclusive. We provide a check for that
* here.
*/
#define DIAGNOSTIC
#ifdef DIAGNOSTIC
if (value != 0 && *where != 0) {
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf("rtl: reloc base_rel(%s): where=%p, *where 0x%lx, "
"addend=0x%lx, base %p\n",
rtems_rtl_obj_oname (obj),
where, *where, rela->r_addend, sect->base);
}
#endif
value += (Elf_Word)(sect->base + *where);
}
mask = RELOC_VALUE_BITMASK (type);
value >>= RELOC_VALUE_RIGHTSHIFT (type);
value &= mask;
if (RELOC_UNALIGNED(type)) {
/*
* Handle unaligned relocations.
*/
char *ptr = (char*) where;
int i, size = RELOC_TARGET_SIZE (type) / 8;
/* Read it in one byte at a time. */
for (i = size - 1; i >= 0; i--)
tmp = (tmp << 8) | ptr[i];
tmp &= ~mask;
tmp |= value;
/* Write it back out. */
for (i = size - 1; i >= 0; i--, tmp >>= 8)
ptr[i] = tmp & 0xff;
} else {
*where &= ~mask;
*where |= value;
tmp = *where;
}
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: %s %p @ %p in %s\n",
reloc_names[ELF_R_TYPE(rela->r_info)],
(void *)tmp, where, rtems_rtl_obj_oname (obj));
return true;
}
bool
rtems_rtl_elf_relocate_rel (const rtems_rtl_obj_t* obj,
const Elf_Rel* rel,
const rtems_rtl_obj_sect_t* sect,
const char* symname,
const Elf_Byte syminfo,
const Elf_Word symvalue)
{
printf ("rtl: rel type record not supported; please report\n");
return false;
}
bool
rtems_rtl_elf_unwind_parse (const rtems_rtl_obj_t* obj,
const char* name,
uint32_t flags)
{
return rtems_rtl_elf_unwind_dw2_parse (obj, name, flags);
}
bool
rtems_rtl_elf_unwind_register (rtems_rtl_obj_t* obj)
{
return rtems_rtl_elf_unwind_dw2_register (obj);
}
bool
rtems_rtl_elf_unwind_deregister (rtems_rtl_obj_t* obj)
{
return rtems_rtl_elf_unwind_dw2_deregister (obj);
}
